Reincarnation And A System?

Lan HO , A teenage student who in a attempt to save the earth, was killed by the on's he tried to protect, only to be reborn with a system? follow Lan HO as he faces hardship and difficulties along his way. this will not be a villain type story but also won't be a hero type story, my character is like, i only do something if it's worth it. kinda guy.